• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

EVGA Nvidia GTX 780 SC ACX - Memory overclocking has absolutely no effect on FPS

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.

RedShores

New Member
Joined
Nov 8, 2014
Hey guys! I have an EVGA Nvidia Geforce GTX 780 SC (Superclocked) ACX (Active Cooling Xtreme) video card. I have been overclocking it using software called EVGA Precision X. I have been benchmarking the overclock with a program called Unigine Heaven Benchmark 4.0 DirectX 11. On Windows 7 64-Bit with 4GB (2 x 2GB) of RAM. With latest Nvidia drivers as of May 18 2015 which is version 352.86. My power Supply is an Antec Basiq Plus at 550w.

With no overclock whatsoever, on a resolution of 1920x1200 (16:10) with Anti-Aliasing turned off, I get 100.8 fps.

When overclocking the Core Clock of the GPU, I was able to get up to +150 mhz with an overvoltage of 1237mv as the highest it would go and still be stable. This gave me an fps of 108.8 on Unigine. Precision X reports my GPU Core clock to be 1241 mhz after the +150 mhz overclock, but a utility called GPU-Z reports it as 1117 mhz. I don't know why there is a difference between the 2 programs, or which one is correct. Does anyone know which program is more trustworthy in reporting this?

The major problem I am having today is that when I attempt to overclock the memory, I get literally no difference in performance at all. I have even gone as high as +700 mhz on the memory with absolutely no extra FPS on Unigine.

The Unigine benchmark DOES report the memory as having increased (with no overclock it shows 3004 mhz, then with +700 it shows 3704 mhz in Unigine)

I have tried the following things that did NOT help:
-Turning KBOOST on and off.
-Trying various voltages, even zero extra voltage.
-Leaving NVidia display driver service on services.msc running or disabled
-Changing fan speeds
-Trying another overclocking utility, MSI Afterburner.

I even tried putting the memory at +2000 mhz which immediately crashed the computer. So it DOES seem to be taking effect, just not actually increasing performance at all. Nothing I do seems to actually make the memory overclock have any effect on the performance of FPS in Unigine.

At this point, I want to mention my previous card which was a MSI Nvidia Geforce GTX 660 Ti with 2GB of GDDR5 Vram. Using the exact same computer and same software, I was able to get very good performance increases on FPS while overclocking the memory on that card.

So here are the possible reasons this could be happening as far as I can guess:

-The Nvidia Geforce 700 series use a microarchitecture called Kepler Refresh. Perhaps there is something different within this microarchitecture that handles how the memory behaves compared to the original Kepler from the 600 series. So that overclocking the memory would only have an effect on things like Anti-Aliasing or extra eye candy like that. Stuff that I had turned off during the benchmark.

-My motherboard is an older model that is still using PCI-Express 2.0 x16. So it is not PCI-Express 3.0 x16 which came out in November 2010. But I have read a few articles online that suggest there no significant difference between these 2 generations of PCI-Express. So I don't think this is the problem. The exact model of the motherboard is GIGABYTE GA-P45T-ES3G LGA 775 Intel P45 ATX Intel Motherboard North Bridge Intel P45 South Bridge Intel ICH10 3gb/s sata 2

-I'm still using an Intel E8400 Wolfdale Core 2 Duo CPU from January 2008. It still uses the Front Side Bus method of talking to the rest of the motherboard. And it uses the old socket type of LGA 775. I'm wondering if this old processor is causing the problems? But my older video card overclocked the memory just fine so I don't think this is the case.

-The Nvidia Geforce GTX 780 I'm using has 3GB of GDDR5 VRam. The older GTX 660 ti I was using only had 2GB of GDDR5 VRam. Perhaps something about having that extra 1GB of ram is related to why the memory overclock doesn't do anything? That maybe the resolution of 1920x1200 is not enough to push the memory? To have an advantage with an overclock?

The GTX 780 I'm currently using seems to work just fine in every other way. Games play fine, videos look good, no odd noises or smells. Color is great, nothing else seems to be strange. The performance of the card in every other aspect is good enough to make me think this issue is by design and not by any defect.

I tried searching with google for anyone else having this problem but could not find anything about this issue so it seems I'm probably unique for the moment.

I'm waiting for Intel Skylake to come out in August or September of this year to upgrade my processor, I suppose at that point I'll see if the motherboard or processor have anything to do with this. But if I had to guess they arn't related to the problem.

So I want to ask the community what they think the problem is with the memory overclocking having no effect on the GTX 780. I would greatly appreciate any information provided by people more knowledgeable than myself. Again thanks for reading my post.
 
It's normal that memory overclocking on the GPU has little to no effect on FPS.

You're definitely hitting a CPU bottleneck, but most likely not limited by the PCIe bus.
 
you are just cpu bottlenecked as atm said.
I have never seen vram or dram help with fps other than in benchmarks
pcie 2.0 or 3.0 doesn't matter in game at all.
the only thing that matters with dram is that it runs in dual channel, triple or quad channel, what ever it's rated for.
for v ram it's 2 gigs to 1080 or so and 4 gigs over that.
 
Actually graphics memory clock helps but in games/tests which are using a lot of memory. However wider bus = lower difference in performance. On GTX960-980 and GTX660-680 memory clock is helping and you can easily see it. On GTX780 , higher AMD cards and probably also on GTX980Ti/Titan it won't change much.
RAM performance is helping in some cases but in most games it doesn't matter.
 
Back